An enlarged thyroid gland (called a goiter), which can appear as a swelling at the base of the neck

Fatigue

Muscle weakness

Difficulty sleeping

Increased appetite

Older adults may have subtle symptoms, such as increased heart rate, increased perspiration and a tendency to become more tired during normal activities.

If your hyperthyroidism is caused by Graves’ disease, you may also have Graves’ opthalmopathy, a disorder that affects your eyes. These symptoms may show up before, after or at the same time as your symptoms of hyperthyroidism. In Graves' opthalmopathy, the muscles behind the eyes swell and push the eyeballs forward. Often, the eyeballs will actually bulge out of their normal position. The front surfaces of the eyeballs become can dry, red and swollen. You may notice excessive tearing or discomfort in your eyes, sensitivity to light, blurry or double vision, and less eye movement.